TROYEN A. BRENNAN is professor of Law and Public Health and professor of Medicine at Harvard School of Public Health and Harvard Medical School. He is the author of Just Doctoring: Medical Ethics in the Liberal State (1991). DONALD M. BERWICK is president and CEO of the Institute for Health Care Improvement in Boston. He is coauthor (with B. Godfrey and J. Roessner) of the best-selling Curing Health Care (Jossey-Bass, 1990).